The invention relates to an apparatus and a method for applying drinking straws to packaging containers. A drinking straw carrier is adapted to keep the drinking straw towards the wall of the packaging container while moving along a lengthwise direction of the drinking straw, from an application position to the leaving position. The drinking straw carrier comprises a rotatable roller having an axis of rotation arranged substantially perpendicular to the lengthwise direction of the drinking straw, and said roller is adapted to rotate in contact with the drinking straw.
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7. A method for applying drinking straws to packaging containers, said method comprises:
conveying drinking straws wrapped in protective envelopes to a picking position by a drive unit,
conveying the packaging containers by a first conveyor at a substantially constant velocity, along a packaging container moving direction,
picking a drinking straw with envelope from the drive unit at the picking position, where the picking is done by an application device, which comprises at least one applicator arm, which applicator arm comprises a drinking straw carrier adapted to carry a drinking straw,
carrying the drinking straw, with the drinking straw carrier, to an application position where the drinking straw is adapted to come into contact with a wall of the packaging container, and further to a leaving position where the at least one applicator arm leaves the drinking straw on the packaging container,
keeping the drinking straw towards the wall of the packaging container, while moving the drinking straw carrier, along a lengthwise direction of the drinking straw, from the application position to the leaving position, said drinking straw carrier being a rotatable roller having an axis of rotation arranged substantially perpendicular to the lengthwise direction of the drinking straw and said roller being arranged to rotate in contact with the drinking straw.
1. Apparatus for applying drinking straws to packaging containers, said apparatus (100) comprises:
a drive unit adapted for conveying drinking straws wrapped in protective envelopes to a picking position,
a first conveyor adapted for conveying packaging containers, at a substantially constant velocity, along a packaging container moving direction, and
an application device which comprises at least one applicator arm, which applicator arm comprises a drinking straw carrier adapted to carry a drinking straw, said at least one applicator arm is adapted to pick a drinking straw from the drive unit at the picking position and carry, with the drinking straw carrier, the drinking straw to an application position where the drinking straw is adapted to come into contact with a wall of the packaging container, and further to a leaving position where the at least one applicator arm leaves the drinking straw on the packaging container, wherein
the drinking straw carrier is adapted to keep the drinking straw towards the wall of the packaging container while moving along a lengthwise direction of the drinking straw, from the application position to the leaving position, and
the drinking straw carrier comprises a rotatable roller having an axis of rotation arranged substantially perpendicular to the lengthwise direction of the drinking straw, which roller is adapted to rotate in contact with the protective envelope and drinking straw.
9. An apparatus for applying drinking straws to packaging containers, the apparatus comprising:
a drive unit configured to convey drinking straws, each wrapped in a protective envelope, to a picking position;
a first conveyor configured to convey, at a substantially constant velocity, packaging containers along a packaging container moving direction; and
an application device that further includes:
a drinking straw carrier configured to carry a respective drinking straw;
an applicator arm configured to pick the respective drinking straw from the drive unit at the picking position and carry the respective drinking straw and the drinking straw carrier to: (1) an application position at which the respective drinking straw is adapted to come into contact with a wall of a respective packaging container, and (2) a leaving position at which the applicator arm leaves the respective drinking straw on the respective packaging container,
wherein the drinking straw carrier is configured to keep the respective drinking straw towards the wall of the respective packaging container as the drinking straw carrier moves along a lengthwise direction of the drinking straw, from the application position to the leaving position, and
wherein the drinking straw carrier further includes:
a rotatable roller, having an axis of rotation arranged substantially perpendicular to the lengthwise direction of the respective drinking straw, that is configured to rotate in contact with the respective drinking straw and corresponding protective envelope.
2. Apparatus according to
3. Apparatus according to
wherein friction between the shaft and the roller is adapted to be less than friction between the protective envelope and an outer contact surface of the roller,
wherein the friction between the protective envelope and the outer contact surface of the roller is less than between the protective envelope and the wall of the packaging container, such that the roller is adapted to start rotating upon contacting the envelope and drinking straw, and such that the drinking straw will not be displaced in relation to the packaging container .
4. Apparatus according to
5. Apparatus according to
6. Apparatus according to
wherein
the application device and the first conveyor are arranged such in relation to each other that, upon application of the drinking straw towards the wall of the packaging container, at the application position, the outer portion of the applicator arm will be forced to rotate around the spring-loaded pivot point thereby creating a force pushing the drinking straw towards the wall of the packaging container.
8. Method according to
wherein the applicator arm comprises a spring-loaded pivot point around which at least an outer portion of the applicator arm can rotate, said outer portion comprises the drinking straw carrier,
wherein
the application device and the first conveyor are arranged such that, in relation to each other, upon application of the drinking straw towards the wall of the packaging container, at the application position, the outer portion of the applicator arm will be forced to rotate around the spring-loaded pivot point, thereby creating a force pushing the drinking straw towards the wall of the packaging container,
wherein said method further:
moving the drinking straw carrier from the application position to the leaving position, in the packaging container moving direction,
maintaining a velocity in the packaging container moving direction as being equal to the constant velocity of the first conveyor, thereby keeping the drinking straw at the same position on the wall of the packaging container, by accelerating or decelerating the rotational velocity of the drive unit to compensate for changes in velocity of the drinking straw carrier, in the packaging container moving direction, due to a changing velocity component, in the packaging container moving direction, of the eccentric rotation round the rotation point and the rotation of at least the outer portion of the applicator arm around the pivot point.
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This is a National Phase of PCT Application No.PCT/EP2016/052151, filed Feb. 2, 2016, which claims the benefit of SE Application No. 1550289-1 filed Mar. 11, 2015, all of which are incorporated herein by reference.
The present invention relates to an apparatus and a method for applying drinking straws to packaging containers.
Many packaging containers for liquid food are manufactured in so-called portion volumes, intended to be consumed direct from the package. The majority of these packages are provided with drinking straws in a protective envelope which is secured to the one side wall of the packaging container. The packaging containers, which are often parallelepipedic in shape, are manufactured from a laminate with a core of paper or paperboard, with layers of thermoplastics and possibly aluminum foil. On the one wall of the packaging container—most often the top wall—a hole has been punched out in the core layer and this hole is covered by the other layers of the laminate, which makes it possible to penetrate the hole with the drinking straw which accompanies the packaging container, and hereby consume the drink enclosed in the package.
There have long been machines which apply drinking straws in their protective envelopes to packaging containers which are conveyed through the machine. Such a machine, i.e. a drinking straw applicator, is, for example, described in the European Patent Specification EP-1,042,172. The applicator functions in that a belt of continuous drinking straw envelopes with drinking straws is guided in towards and surrounds a drive means. Adjacent the drive means, there are devices for severing the drinking straw belt into individual drinking straws enclosed in a protective envelope, as well as devices for applying the drinking straw to one side wall of the packaging container, the packaging container being advanced on a conveyor through the machine. Prior to the moment of application, the envelope drinking straw is provided with securement points. The securement points may, for example, consist of hot melt, which is molten glue which glues the drinking straw envelope in place and retains it when the glue has hardened.
Today straw applicators may operate in ultra high speeds, handling approximately 40,000-50,000 packages/hour. The Swedish patent application No. 1451136-4 describes an ultra high speed straw applicator.
One issue with straw applicators, irrespective of operational speeds, is the difficulty of retaining the drinking straw on the wall of the packaging container at exactly the same position, with an application device, while at the same time conveying the packaging container through the straw applicator. If the application device and the conveyor, on which the packaging container is transported, become un-synchronised, even just slightly, the drinking straw will lose its position on the packaging wall and the glue will smear. In most cases the end result will only be a less attractive packaging container, but in a worst case the bonding strength between the drinking straw and the packaging container is considerably reduced, with an increased risk that the drinking straw will detach from the packaging container during handling. The Swedish patent application No. 1451542-3 describes a solution in which the drinking straw is not moved, relative the packaging container, in the direction of the conveying direction, i.e. in the direction in which the packaging container is moved during application. The movement of the application device is compensated such that the application device will, during the application, follow the drinking straw in the lengthwise straw direction.
Another issue that may still exist is that the drinking straw is undesirably moved, relative to the packaging container, in the lengthwise direction of the drinking straw. Such movement may cause smear of the glue and there will be a risk that the drinking straw is not properly attached to the packaging container. The movement is caused by friction between the envelope of the drinking straw and the contact surface of application device.
One object of the present invention is therefore to provide an apparatus for applying drinking straws to packaging containers, which apparatus improves the positioning and retaining of the drinking straw in a correct position. According to a first aspect of the invention, the object is solved by an apparatus for applying drinking straws to packaging containers. Said apparatus comprises a drive means adapted for conveying drinking straws wrapped in protective envelopes to a picking position. It further comprises a first conveyor adapted for conveying packaging containers, at a substantially constant velocity, along a packaging container moving direction. The apparatus further comprises an application device which comprises at least one applicator arm, which applicator arm comprises a drinking straw carrier adapted to carry a drinking straw. Said at least one applicator arm is adapted to pick a drinking straw from the drive means at the picking position and carry, with the drinking straw carrier, the drinking straw to an application position where the drinking straw is adapted to come into contact with a wall of the packaging container, and further to a leaving position where the at least one applicator arm leaves the drinking straw on the packaging container. The drinking straw carrier is adapted to keep the drinking straw towards the wall of the packaging container while moving along a lengthwise direction of the drinking straw, from the application position to the leaving position, and the drinking straw carrier comprises a rotatable roller having an axis of rotation arranged substantially perpendicular to the lengthwise direction of the drinking straw, which roller is adapted to rotate in contact with the protective envelope and drinking straw.
In one or more embodiments the roller is rotatably journalled on a shaft of the applicator arm and is adapted to rotate due to friction from the protective envelope and drinking straw.
In one or more embodiments friction between the shaft and the roller is adapted to be less than friction between the protective envelope and an outer contact surface of the roller, wherein the friction between the protective envelope and the outer contact surface of the roller is less than between the protective envelope and the wall of the packaging container, such that the roller is adapted to start rotating upon contacting the envelope and drinking straw, and such that the drinking straw will not be displaced in relation to the packaging container.
Furthermore, in one or more embodiments the roller is made of a plastic material with a low coefficient of friction and a high resistance to abrasion.
In one or more further embodiments the roller is shaped as an axisymmetric, concave cylinder adapted to carry the drinking straw with a concave centre bounded by two end flanges.
In one or more embodiments the at least one applicator arm has a base end point arranged for eccentric, substantially circular rotation round a rotation point, the rotation point being connected to a drive unit adapted to provide a rotational velocity. The applicator arm comprises a spring-loaded pivot point around which at least an outer portion of the applicator arm can rotate. Said outer portion comprises the drinking straw carrier. The application device and the first conveyor are arranged such in relation to each other that, upon application of the drinking straw towards the wall of the packaging container, at the application position, the outer portion of the applicator arm will be forced to rotate around the spring-loaded pivot point thereby creating a force pushing the drinking straw towards the wall of the packaging container.
According to a second aspect of the invention, the object is solved by a method for applying drinking straws to packaging containers. Said method comprises the step of conveying drinking straws wrapped in protective envelopes to a picking position by means of a drive means. The method further comprises the step of conveying the packaging containers by a first conveyor at a substantially constant velocity, along a packaging container moving direction. The method further comprises the step of picking a drinking straw with envelope from the drive means at the picking position by means of an application device which comprises at least one applicator arm, which applicator arm comprises a drinking straw carrier adapted to carry a drinking straw. The method further comprises the step of carrying the drinking straw, with the drinking straw carrier, to an application position where the drinking straw is adapted to come into contact with a wall of the packaging container, and further to a leaving position where the at least one applicator arm leaves the drinking straw on the packaging container. The method further comprises the step of keeping the drinking straw towards the wall of the packaging container, with the drinking straw carrier, while moving the drinking straw carrier along a lengthwise direction of the drinking straw, from the application position to the leaving position, said drinking straw carrier being a rotatable roller having an axis of rotation arranged substantially perpendicular to the lengthwise direction of the drinking straw and said roller being arranged to rotate in contact with the drinking straw.
In one or more embodiments the at least one applicator arm has a base end point arranged for eccentric, substantially circular rotation round a rotation point, the rotation point being connected to a drive unit adapted to provide a rotational velocity. The applicator arm comprises a spring-loaded pivot point around which at least an outer portion of the applicator arm can rotate, said outer portion comprises the drinking straw carrier. The application device and the first conveyor are arranged such in relation to each other that, upon application of the drinking straw towards the wall of the packaging container, at the application position, the outer portion of the applicator arm will be forced to rotate around the spring-loaded pivot point thereby creating a force pushing the drinking straw towards the wall of the packaging container. Said method comprises the step of moving the drinking straw carrier from the application position to the leaving position, in the packaging container moving direction, maintaining a velocity in that direction being equal to the constant velocity of the first conveyor, thereby keeping the drinking straw at the same position on the wall of the packaging container, by accelerating or decelerating the rotational velocity of the drive unit to compensate for changes in velocity of the drinking straw carrier, in the packaging container moving direction, due to a changing velocity component, in the packaging container moving direction, of the eccentric rotation round the rotation point and the rotation of at least the outer portion of the applicator arm around the pivot point.
One embodiment of the present invention will now be described in greater detail hereinbelow, with reference to the accompanying drawing, in which:
The drawings show only those details essential to an understanding of the present invention, and the remaining parts of the apparatus, which are well-known to a person skilled in the art, have been omitted.
On its circumferential surface, the drive means 1 has a number of recesses 6 which are each intended for one drinking straw 3. The number of recesses 6 on the drive means 1 depends on the thickness and design of the drinking straw 3, and the pitch between straws in the belt. In a conventional belt of straight and telescopic straws the pitch is e.g. 15 mm, whereas for U-shaped straws the pitch is e.g. 22 mm.
Between each recess 6 on the circumferential surface of the drive means 1, there is disposed a groove 7. The groove 7 is intended to receive a knife 9 of a separation device 8 for separating individual drinking straws 3, and their envelopes, from the belt 2.
The separation device 8, for separating the drinking straws 3, comprises the knife 9, which knife 9 is fixedly mounted in a holder 10. The holder 10 is journalled on an eccentric shaft 11. A centre shaft of a disc 12, to which the eccentric shaft 11 is fixed, is driven by the first servo motor via the same belt and/or cogwheels/gears driving the drive means 1. Hence, the separation device 8 and the drive means 1 are mechanically interconnected and both the rotation of the drive means 1 and the motion of the separation device 8 are driven by the first servo motor. Further, the knife holder 10 is journalled in an axial bearing 13, which bearing is fixedly attached to a rod 14 rotatably journalled around the centre shaft 15 of the drive means 1.
The apparatus 100 further includes an application device 16 for applying a drinking straw 3 on one side wall 18 of a packaging container 17. The application device 16 comprises two applicator arms 19. With two cooperating applicator arms 19, a more reliable and efficient placing of the drinking straws 3 on the side wall 18 of the packaging containers 17 will be obtained.
The arms 19 are oriented above one another and are united by means of a bracket 20, which may in principle consist of an extension of the applicator arms 19. The bracket 20 is journalled in two eccentric shafts 21, 22 which have the same eccentricity. The drive means 1 is provided with parallel grooves (not shown) along its circumference. The applicator arms 19 are arranged to move in these grooves, and at at least one point be arranged in between the drive means and a separated straw 3, to be able to pick the straw 3 and carry it towards the side wall 18 of a packaging container 17. The application device 16 is driven by a second motor (not shown), e.g. a servo motor, of the drive unit. The second servo motor drives the application device 16 via a belt and/or cogwheels/gears.
The apparatus 100 further comprises a first, lower conveyor 23, passing by the drive means 1, for conveying the packaging containers 17 which are to be supplied with drinking straws 3. The conveyor 23 may consist of an endless, driven belt. Only a portion of the conveyor is shown in
The drive means 1, the application device 16 and the separation device 8 are designed such that it may be variably inclined in relation to the conveyor 23. In this way the packaging containers 17, which are advanced with their bottom surface bearing on the horizontal conveyor 23, will have the drinking straws 3 placed in the desired angle of inclination on the side wall 18. The inclination depends on both the volume of the packaging container 17 and on the size and shape of the drinking straw 3.
The drive means 1, which is disposed to rotate continuously during operation, is the central unit in the apparatus 100, see
The separation device 8, for separating a straw 3, in its envelope, from the rest of the belt 2 executes two movements during each separation cycle. On the one hand, the knife 9 reciprocates radially in relation to the drive means 1 and into the groove 7 in order to be able to separate one drinking straw 3 from the belt 2. On the other hand, the separation device 8 must accompany the continuously rotating drive means 1 during that time when the separation cycle is in progress. These two movements are simultaneously achieved by means of the eccentricity of the shaft 11 and the alternating, pivoting motion (counterclockwise and clockwise) of the rod 14 around the shaft 15 of the drive means 1.
Once the separation cycle is completed and the knife 9 has severed one drinking straw 3, in its protective envelope, from the continuous belt 2, the separation device 8 returns to its starting position and begins a new separation cycle.
The first conveyor 23 moves tangentially in relation to the drive means 1 and conveys the packaging containers 17, which are to be provided with drinking straws 3, past the drive means 1. The first conveyor 23 moves at a speed which is synchronised with the speed of the drive means 1, the separation device 8 and the application device 16. Before the separated straws 3 are picked by the application device 16, their envelopes have been provided, on one of their side surfaces, with securement points, preferably two in number, which may, for example, consist of glue, preferably so called hot melt. The securement points are to glue in place and, once the hot melt glue has set, retain the drinking straw 3 in its protective envelope against the side wall 18 of the packaging container 17.
The application device 16 for applying drinking straws 3 on the side walls 18 of the packaging containers 17 describes, by means of the two eccentric shafts 21, 22, a circular or alternatively elliptic movement so that the arms 19 move in towards the drive means 1 and entrap a drinking straw 3. The drinking straw 3 is moved by the rotating movement towards the side wall 18 of the packaging container 17 and is kept in position by means of the securement points. As a result of the second servo motor and requisite gear ratios, the applicator arms 19 now move at the same speed at which the conveyor 23 (and thereby also the packaging container 17) moves, and the applicator arms 19 accompany, in their rotating movement, the packaging container 17 and the conveyor 23 a short distance before the rotational movement recuperates the applicator arms 19 back to their starting position where they begin a new application cycle.
By means of
The sensing device 28 is positioned at a fixed distance from the position where the application device 16 applies the straw 3 onto the packaging container 17. Passage of a packaging container sends a signal to a control device (not shown) of the apparatus, e.g. a PLC, which will time the movements of the drive means 1, separation device 8 and the application device 16 based on the detection of the packaging container being transported on the lower conveyor 23. The timing is made by accelerating or decelerating the first and second servo motors of the drive unit and in that way the straw will be applied at a correct position on the packaging container once the packaging container reaches the application device 16. Hence, with regard to the sensing device 28 and the control device any distance between the packaging containers can be dealt with, e.g. if the distance between succeeding packaging containers is not exactly equal, or even highly differs between two succeeding packaging containers, it will still work since the application cycle is individually timed for each passing packaging container by acceleration or deceleration of the first and second servo motors.
In
The pitch control device 25 is arranged upstream the drive means 1 and comprises a packaging container deceleration device 26, e.g. a belt brake, and a second, upper conveyor 27.
The deceleration device 26, being a belt brake in this embodiment, is arranged upstream the sensing device 28 and the second upper conveyor 27. The belt brake has belts 26a, 26b on each side of the lower conveyor 23. The belts 26a, 26b are partly running in parallel with the transported packaging containers 17 in such a way that said belts are adapted to come into contact with two opposed side walls of each packaging container, and decelerate and transport the packaging container at a velocity being less than that of the conveyor 23. Hence, the belts 26a, 26b are adapted to create higher friction against the packaging container 17 than the friction between the packaging container 17 and the lower conveyor 23. The packaging container will thus slide against the lower container 23 and queue up, or line up, in the belt brake 26.
The second, upper conveyor 27 is arranged above a portion of the first, lower conveyor 23, and is adapted to help transporting the packaging containers by supporting their top surface. The upper conveyor also keeps track of the position of the packaging container in relation to the application device, in that a third motor (not shown), for example a servo motor, used for driving the conveyor, is used, based on the servo motor speed, to calculate the time before the packaging container passes the application device. The upper conveyor 27 comprises a belt 30 adapted to bear against the top surface of the packaging container. The upper conveyor 27 is positioned such that it will come into contact with a packaging container while the packaging container is about to leave the belt brake 26. This position, where the upper conveyor 27 contacts the packaging container 17, is upstream the sensing device 28. The distance between the packaging container transport surface of the lower conveyor 23 and the lower end of the belt 30 of the upper conveyor 27 equals the packaging container height, and can be adjusted to fit different packaging container sizes. Preferably, for this reason, the upper conveyor 27 is displaceable in relation to the lower conveyor 23.
The pitch control device 25 operates as follows. The velocities of the first, lower conveyor 23 and the second, upper conveyor 27 are set substantially equal. The velocity of the belts 26a, 26b of the belt brake 26 is set to be slower. Hence, as mentioned above, the packaging containers 17 will queue up once reaching the belt brake 26. Upon advancement of the packaging containers 17 through the belt brake 26, the packaging containers 17 will reach the downstream end of the belt brake 26. Just before leaving the belt brake 26 the packaging container will reach the upstream end of the upper conveyor 27. The upper and lower conveyors 23, 27 will then “pick” the packaging container 17 at the downstream end of the belt brake 26, and change its velocity to that of the upper and lower conveyors 23, 27. Due to the lower velocity of the belt brake 26, compared to that of the upper and lower conveyors 23, 27, the “picking” action will create a distance, pitch P (
A pitch set point value Ps is set (not shown). This is the ideal pitch for the capacity in terms of velocity and acceleration, for which the apparatus is designed. The pitch set point value Ps will be the same irrespective of the size of the packaging container, for sizes within an operational range of the apparatus. This means that the pitch will be the same for all packaging containers to be processed through the apparatus. With a fixed, pre-set pitch vibrations in the apparatus can be considerably minimised since the mechanics can be dimensioned and balanced for said pitch. This is further described in the Swedish patent application No. 1451136-4.
The drive unit is driven at a substantially constant speed, i.e. with a minimum of acceleration variations, as much as possible minimizing frequent, considerable accelerations and decelerations of the servo motors of the drive unit. The speeds of the servo motors are set by the apparatus' control device, which also controls the synchronization of the movements of the drive means 1, the separation device 8 and the application device 16, as well as of the conveyors transporting the packaging containers. If the pitch is set to 80 mm the drive unit will not go down into stop/standby mode (standstill of drive unit) if there is a packaging container coming within a pitch of 130 mm. It will decelerate some.
So far the general function of the apparatus 100 has been described. In the following the application device 16 will be described in more detail with reference to
As mentioned above the application device 16 comprises a pair of applicator arms 19 oriented above one another and united by means of a bracket 20. Only the uppermost applicator arm is shown in
As mentioned the pair of applicator arms 19 is able to pick a drinking straw 3 from the drive means 1. The drive means 1 in this embodiment is cylindrical and the drinking straws 3 in their envelopes are kept on the outer circumferential surface. The straw extension is parallel to the axial axis α of the cylindrical drive means 1. The drive means rotates in order to advance drinking straws 3 to a picking position A (shown in
In this embodiment one drinking straw 3 is advanced per division and is made available at the picking position A where the application device 16, and i.e. the applicator arm 19, can pick it. The time available for rotating one division depends on the pitch P between the packaging containers. Since the speed of the first conveyor 23 is kept constant, the time period for bringing another packaging container in position for straw application will depend on the pitch. As mentioned above the pitch between successive packaging containers is detected by the sensing device 28, and the motion of the drive means 1 is adapted to fit the corresponding pitch.
Each applicator arm 19 comprises two portions (see
The drinking straw carrier 42 as well as a portion of the second portion 19b of the applicator arm 19 is shown in more detail in
The drinking straw will be positioned on the wall of the packaging container 17 in a package point 44. The velocity, shown as the arrow denoted vc, of the first conveyor 23 is substantially constant. Hence, the packaging container 17 will move at the same a constant velocity vc In order to maintain the drinking straw 3 exactly at the package point 44 on the wall of the packaging container, the displacement of the drinking straw carrier 42 of the applicator arm 19 needs to move with the exact same constant velocity. Otherwise the drinking straw will be dragged along the packaging container and the glue will smear. Further, in order for the drinking straw to securely attach to the packaging container, the applicator arm 19 needs to firmly hold the drinking straw 3 by exerting a slight pressure onto the packaging container 17.
The pressure is solved in that the eccentric, circular path of at least the end 40 of the application device 16 is at least in theory overlapping the linear path L of the first conveyor 23, from the application position, i.e. first moment of contact between the drinking straw 3 and the packaging container 17, to the leaving position. This is illustrated by
The eccentric circular movement of the application device, as well as the resilience of the second portion 19b by means of the spring-loaded pivot point D, will give rise to a varying velocity of the drinking straw carrier 42 between the application position and the leaving position. Accordingly, the drinking straw 3 will not be kept at the package point 44 throughout the movement along line L.
However this has been solved. It has been realised that the variation in velocity have two causes. The first cause is the fact that the application device is eccentrically moved around the rotation point C, the second cause is the fact that the spring changes the movement of the drinking straw carrier.
Calculations have shown that the horizontal component cvr of the rotation velocity vr will be larger than the horizontal component cvs of the velocity vs round the pivot point D. Hence, the net effect is that the servo motor of the drive unit needs to compensate by decelerating at least at the application position F, preferably start decelerating before the application point F and continue some time after passing the application position F. Further, upon leaving the drinking straw 3, at least at the leaving position G, the servo motor needs to compensate by accelerating.
In other words, the drinking straw carrier 42 can be moved from the application position F to the leaving position G, maintaining a velocity in the packaging container moving direction, being equal to the constant velocity vc of the first conveyor 23. This is accomplished by accelerating the rotational velocity vr of the drive unit to compensate such that the net balance of the velocity components cvr, cvs, in the packaging container moving direction, of the eccentric rotation round the rotation point C and the rotation of at least the outer portion 19b of the applicator arm 19 around the pivot point D, is at all times equal to the constant velocity vc.
The decelerating and the accelerating of the servo motor will have to be adjusted to the conditions of each specific apparatus and to the exactness needed.
In the previous it has been described how the drinking straw 3, by servo motor compensation, is kept at the same position on the wall of the packaging container, in relation to the conveying direction. With regard to
As mentioned the applicator arms 19 will follow the lengthwise direction of the drinking straws, i.e. follow the earlier described axis K, from the application position F to the leaving position G. The rollers 46, each having a rotation axis R being perpendicular to the axis K, will roll along the drinking straw 3 in contact with the protective envelope 52. The shaft and the roller 46 are designed such that the friction between the shaft and the roller is less than the friction between the protective envelope 52 and an outer contact surface of the roller 46. Further, the friction between the protective envelope 52 and the outer contact surface of the roller 46 should be designed such that it is less than the friction between the protective envelope 52 and the wall of the packaging container 17. In this way it is secured that the roller 46 will start rotating upon contacting the drinking straw 3 (i.e. the envelope 52). Hence, a displacement of the drinking straw with envelope, in relation to the packaging container, is prevented, also in the lengthwise direction of the drinking straw. Hence, it can be secured that the drinking straw 3 will be kept exactly at the previously described package point 44.
It is to be understood that the glue or adhesive used will highly influence the friction between the packaging container wall and the drinking straw with envelope.
From the application position F to the leaving position G the rollers 46 will roll a distance of approximately a few millimeters on the packaging container.
So far the motion of the application device from a picking position A to a leaving position G has been described. However, that is only a portion of the entire motion cycle performed by the application device 16 per drinking straw application. The entire motion cycle can be divided into two portions. In a first portion I, shown in
In a second portion II of the motion cycle the applicator arms 19 move from the leaving position G back to the application position F to apply a drinking straw onto a successive packaging container. The second portion II includes passing the picking position A such that the applicator arm can pick a successive drinking straw from the drive means 1, i.e. the drinking straw feed wheel, and carry it to the application position F. Said second portion II, unlike the first portion I, varies between packaging containers. Hence, it is “dynamic” in the sense that it is adjusted to fit the pitch P between successive packaging containers 17 on the first conveyor 23. In an ideal case the pitch P to the successive packaging container 17 is equal to the set point pitch value Ps. If the pitch P to a successive packaging container is shorter than the set point pitch value Ps, the motion from the leaving position G back to the application position F needs to be performed faster than for the set point pitch value Ps. If, on the other hand, the pitch to a successive packaging container is instead longer than the set point pitch value Ps, the motion back needs to be performed slower. The transition from the second portion II to the first portion I, at the application position F, is made such that the rotational velocity vr provided by the servo motor in the drive unit is equal to an application velocity va and the acceleration is equal to an application acceleration aa. The application velocity va and the application acceleration a a will be the same for all successive packaging containers, i.e. for each motion cycle. The transition from the first portion I to the second portion II, at the leaving position G, is made such that the rotational velocity vr provided by the servo motor in the drive unit is equal to a leaving velocity v1 and the acceleration is equal to a leaving acceleration a1. The leaving velocity v1 and the leaving acceleration a 1 will be the same for all successive packaging containers, i.e. for each motion cycle.
The application acceleration a a is the acceleration needed in the application position F such that the drinking straw carrier 42 can be moved with a velocity equal to the velocity vc of the first conveyor 23. Hence, the acceleration compensates, in that moment, such that the net balance of velocity components cvr, cvs, in the packaging container moving direction, of the eccentric rotation round the rotation point C and the rotation of at least the outer portion 19b of the applicator arm 19 around the pivot point D, is equal to the constant velocity vc. The application velocity va is such that the component of it, in the direction of the packaging container movement, is equal to the packaging container velocity vc, i.e. equal to the velocity of the first conveyor 23.
The leaving acceleration a 1 is the acceleration needed in the leaving position G such that the drinking straw carrier 42 can be moved with a velocity equal to the velocity vc of the first conveyor 23. Hence, the acceleration compensates, in that moment, such that the net balance of velocity components cvr, cvs, in the packaging container moving direction, of the eccentric rotation round the rotation point C and the rotation of at least the outer portion 19b of the applicator arm 19 around the pivot point D, is equal to the constant velocity vc. The leaving velocity v1 is such that the component of it, in the direction of the packaging container movement, is equal to the packaging container velocity vc, i.e. equal to the velocity of the first conveyor 23.
The key to accomplish a smooth operation is to limit abrupt or considerable accelerations. Any change in acceleration will be made as smooth as possible, as sudden acceleration changes will cause unnecessary vibrations to the apparatus 100 and strains in the servo motors of the drive unit. Hence, if detecting a pitch P between two successive packaging containers 17 which is shorter than a set point pitch value Ps, the second portion II of the motion cycle will be adapted by smoothly accelerating from the leaving velocity v1 and the leaving acceleration a 1 and then smoothly decelerating such that, at the application position F, the application velocity va and the application acceleration a a have been reached. Similarly, if detecting a pitch P between two successive packaging containers 17 which is longer than a set point pitch value Ps, the second portion II of the motion cycle will be adapted by smoothly decelerating from the leaving velocity v1 and then smoothly accelerating such that, at the application position F, the application velocity va and the application acceleration a a have been reached.
The adaptation of the second portion II of the motion cycle is made by the previously described control device, which control device is connected to the drive unit driving the drive means 1 and the application device 16.
The present invention should not be considered as restricted to the embodiment described above and shown in the drawings. It is apparent for a person skilled in the art that many modifications are being conceivable without departing from the scope of the appended claims.
For example, an apparatus according to the present invention may instead be employed for applying other objects such as, for example, spoons or the like which are intended to accompany the package 17 to the consumer.
In the embodiment described each applicator arm 19 comprises two portions 19a, 19b, where the outermost piece is being rotatably journalled in the other in the pivot point D. The rotation in the pivot point D is springloaded by means of a compression spring 44 in order to apply a force towards the packaging container for holding the drinking straw firmly on the wall. Alternatively, each applicator arm 19 is manufactured as one piece. The base point B is then provided also with the pivoting function. The base point is then springloaded with a torsion spring to be able to apply force onto the packaging container 17.
Olsson, Lennart, Berglin, Michael
Patent | Priority | Assignee | Title |
10640252, | Dec 15 2014 | TETRA LAVAL HOLDINGS & FINANCE S A | Method of operating an apparatus for applying drinking straws to packaging containers and an apparatus operated by the method |
Patent | Priority | Assignee | Title |
4293369, | Jan 30 1978 | Aktiebolaget Tetra Pak | Machine for the application of suction tubes to packing containers |
4384441, | Jul 11 1979 | Aktiebolaget Tetra Pak | Machine for wrapping elongated articles in plastic film |
4572758, | Feb 13 1984 | Indag Gesellschaft fur Industriebedarf mBH | Machinery and method for attaching drinking straws in protective coverings to beverage containers |
4584046, | Feb 05 1982 | Device for attaching articles to packages, bottles and other objects | |
4584819, | Jun 23 1983 | Aktiebolaget Tetra Pak | Arrangement for the application of objects to packing containers |
4903458, | Sep 04 1987 | AB Tetra Pak | Arrangement for the attachment of bendable, elongated objects, in particular suction tubes, along the side of a packing container |
4969308, | Jul 15 1988 | Tetra Pak Finance & Trading S.A. | Method of attaching a drinking straw to a pack and apparatus for carrying out the method |
5037366, | May 17 1990 | Gilliland Industrials Corporation | Device for attaching a straw to a carton container |
5676629, | Feb 18 1994 | Tetra Laval Holdings & Finance S.A. | Method and an apparatus for transferring tabs to a continuous material web |
5979142, | Oct 16 1997 | INDAG GESELLSCHAFT FUER INDUSTRIEBEDARF MBH & CO BETRIEBS KG | Straw attaching apparatus |
6282865, | May 16 1997 | Tetra Laval Holdings & Finance S.A. | Apparatus for applying drinking straws |
6526725, | Jun 23 1999 | Shrink Packaging Systems Corporation | Apparatus and method for attaching straws to containers |
8870729, | Feb 06 2008 | TETRA LAVAL HOLDINGS & FINANCE S A | Straw applicator |
9527618, | Mar 28 2002 | CAPRI SUN GMBH | Procedure and device for sticking objects |
20010002532, | |||
20100300040, | |||
20110036053, | |||
20180029737, | |||
EP121056, | |||
EP305789, | |||
EP1042172, | |||
SE14511364, | |||
SE14515423, | |||
WO2016045921, | |||
WO2016096379, | |||
WO9851572, |
Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
Feb 02 2016 | Tetra Laval Holdings & Finance S.A. | (assignment on the face of the patent) | / | |||
Jul 12 2017 | BERGLIN, MICHAEL | TETRA LAVAL HOLDINGS & FINANCE S A | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 043267 | /0951 | |
Jul 12 2017 | OLSSON, LENNART | TETRA LAVAL HOLDINGS & FINANCE S A | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 043267 | /0951 |
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